The present invention is concerned generally with orthopedic chairs and, more particularly, with those intended for use in hospitals, nursing homes and geriatric care centers.
Hospital patients, nursing home residents and particularly non-ambulatory geriatric patients may spend many consecutive hours in seated positions. When such a person is seated in a conventional padded chair for prolonged periods of time, pressure exerted on the tissues adjacent the ischial tuberosities on the base of the hip bone may lead to breakdown of these tissues, resulting in the formation of decubitus ulcers.
Existing chairs generally have a padded seating unit disposed over a hard surface. The seating unit of these chairs tends to "bottom out" over a period of time against the hard surface in response to the weight of the chair user, thereby exerting pressure on the tissues adjacent the ischial tuberosities. The hips of a person seated in a conventional hospital chair also tend to tilt anteriorly, exerting shear on the tissues adjacent the ischial tuberosities. The pressure and shear exerted on these tissues during prolonged seating cause discomfort to the user and contribute to the formation of decubitus ulcers.
The preferred seating position of infirm persons may vary with individual physical characteristics and desires. For example, the seat height of a hospital or geriatric chair should allow an ambulatory user to attain a seated position without an abrupt drop, to rest his or her feet on the ground while in a seated position, and to rise from a seated to a standing position with a minimum of difficulty. A person using a chair with too high a seat is likely to experience discomfort and difficulty in rising to a standing position because his lower legs and feet are dangling from the forward edge of the seat rather than resting on the ground. Similarly, a person using a chair with too low a seat is likely to experience difficulty in lowering his body to a seated position without an abrupt drop and in rising to a standing position. Hence, a short person may require a lower seat height than a tall person and vice versa. In addition, male users generally prefer a more reclined seat back angle than female users.
Existing hospital or geriatric chairs are either static, i.e., formed with fixed seating positions, or are equipped with relatively expensive mechanical devices for adjusting seat and/or back positions. The relatively inexpensive conventional static chairs have limited utility since they cannot be adjusted to the seating preferences or needs of a particular user nor readjusted to suit a subsequent user. For example, a "hip chair" seating position, in which the front of the seat is inclined downward relative to the back of the seat, is often recommended for people afflicted with certain hip problems to assist in maintaining the hip joint in the proper position. Existing orthopedic chairs generally provide seating positions in which the front of the seat is even with or inclined upward relative to the back of the seat. Such chairs are not adapted to provide a "hip chair" adjustment without resort to improvisation with cushions or other support means which may shift out of position in response to a user's movements. Hence, use of existing hospital chairs by persons for whom a hip chair is recommended may cause discomfort, or perhaps even exacerbate the hip condition or delay post-surgical recovery.
Infirm persons may experience a loss of muscle strength, particularly in the upper thighs, making it difficult to rise from a seated position to a standing position. Infirm persons also may experience difficulties in visually perceiving the spatial relationship between an object and the position of his body, making it difficult for such a person to align himself in the proper position for seating himself in a chair. Such persons tend to rely on chair arms to provide leverage in rising from a seated position to a standing position, and to assist in locating the chair position prior to and while being seated. The arms of existing geriatric chairs generally do not extend as far as the forward edge of the seat, thereby diminishing their ability to assist an infirm user in reaching seated or standing positions.
Infirm persons who remain seated in geriatric chairs for prolonged periods commonly rest their elbows upon armrests provided on such chairs. The armrests of existing chairs often tend to "trap" the ulnar or radial nerves located near the user's elbow, resulting in numbness and loss of strength of the user's hands.
Infirm persons may experience conditions such as incontinence, seepage from wounds, or other discharges of bodily fluids which necessitate cleaning and disinfection of their chairs. Existing geriatric chairs generally are not constructed to permit disassembly for thorough cleaning and disinfection of all chair surfaces, and therefore may harbor microbial growth and unpleasant odors.
Infirm persons who suffer from dementia may tend to pick at surfaces conveniently within their reach, such as the side panels of the chairs in which they are seated, eventually causing damage to these surfaces. Existing geriatric chairs generally are not constructed to permit ready replacement of damaged components thereof, so damaged chairs must either be discarded or sent out for relatively expensive repairs.
It is believed that geriatric or hospital chairs having a fashionable appearance improve the self-image and morale of infirm persons, promote the voluntary use of such chairs, and tend to increase the social interaction of a person seated therein. Unfortunately, existing chairs for use by infirm persons generally have an institutional appearance.
Accordingly, the present inventors were faced with the problem of devising a hospital or geriatric chair which overcomes the foregoing drawbacks of conventional chairs of this type.